title: microRNAs Involved in Regulating Spontaneous Recovery in Embolic Stroke Model.
abstract: To date, miRNA expression studies on cerebral ischemia in both human and animal models have focused mainly on acute phase of ischemic stroke. In this study, we present the roles played by microRNAs in the spontaneous recovery phases in cerebral ischemia using rodent stroke models. Brain tissues were harvested at different reperfusion time points ranging from 0-168 hrs after middle cerebral artery occlusion using homologous emboli. MiRNA and mRNA expression profiles were investigated by microarray followed by multiple statistical analysis. Candidate transcripts were also validated by quantitative RT-PCR. Three specific groups of miRNAs were observed among a total of 346 differentially expressed miRNAs. miRNAs, miR-21, -142-3p, -142-5p, and -146a displayed significant upregulation during stroke recovery (48 hrs to 168 hrs) compared with those during acute phases (0 hrs to 24 hrs). On the other hand, an opposite trend was observed in the expression of miR-196a/b/c, -224 and -324-3p. Interestingly, miR-206, -290, -291a-5p and -30c-1*, positively correlated with the infarct sizes, with an initial increase up to 24hrs followed by a gradual decrease from 48 hrs to 168 hrs (R = 0.95). Taken together with the expression levels of corresponding mRNA targets, we have also found that Hedgehog, Notch, Wnt and TGF-β signaling pathways could play significant roles in stroke recovery and especially in neuronal repair.
authors.affiliation: Department of Biochemistry, Center for Translational Medicine, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore, Singapore ; Department of Pharmacology, Center for Translational Medicine, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Singapore, Singapore.
authors.forename: Fu Jia
authors.initials: FJ
authors.lastname: Liu
authors.forename: Kai Ying
authors.initials: KY
authors.lastname: Lim
authors.forename: Prameet
authors.initials: P
authors.lastname: Kaur
authors.forename: Sugunavathi
authors.initials: S
authors.lastname: Sepramaniam
authors.forename: Arunmozhiarasi
authors.initials: A
authors.lastname: Armugam
authors.forename: Peter Tsun Hon
authors.initials: PT
authors.lastname: Wong
authors.forename: Kandiah
authors.initials: K
authors.lastname: Jeyaseelan
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004195:Disease Models, Animal; D018450:Disease Progression; D004617:Embolism / Q000150:complications*; D008297:Male; D051379:Mice; D035683:MicroRNAs / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D020521:Stroke / Q000209:etiology / Q000503:physiopathology*; D059467:Transcriptome
chemical_list: D035683:MicroRNAs